FLAGELLATE INFUSORIA AND ALLIED ORGANISMS. 99 



II. Protozoa Flagellata resembling Rhizopoda. 



1- A Flagellate with nuclearia-like rhizopod con- 

 dition- — Tliis organism has been shortly described by Cien- 

 kowski^ as Ciliophrys inftisionum; it has been twice found 

 tinder the same conditions in considerable numbers,viz.inpond 

 water which had stood some time in the house and had become 

 somewhat foul ; in one case, in company with a large quan- 

 tity of Antophysa vegetans, and many other Flagellata, such 

 as are usually found in foul ditch water. The organism is 

 tolerably large, 0*03 mm. in length, but varying considerably 

 in size. It is considerably elongated (fig. 24, a), and is some- 

 what tapering anteriorly ; the front end, which bears the 

 flagellum, is somewhat sharply truncated. The posterior 

 end is usually rounded, and is sometimes drawn out into 

 a tail-like appendage. This, however, appears only to be 

 the case when the organism is passing into its rhizopod 

 condition. A nucleus and contractile vacuole, both in a 

 constant position, are seen within the protoplasm, which is 

 tolerably clear. The nucleus lies at the front of the body, 

 close below the base of the flagellum ; whilst the contractile 

 vacuole is about the centre, or somewhat above it, close under 

 the surface. Other vacuoles, which are not contractile, are 

 usually found, and near them large dark granules, sometimes 

 of a greenish colour ; these can only be looked upon as in- 

 gested food materials. Many secretion-granules are also 

 present, heaped together at the posterior end. 



If a moderately active Flagellate of this form be kept under 

 observation for some time, it will often be found that the 

 movement becomes slower, whilst the circumference becomes 

 irregular. Fine pseudopodia are gradually thrust out, and 

 to the destruction of the flagellum the organism becomes 

 converted into a rhizopod form (fig. 24 b). 



In this condition it closely resembles Cienkowski's Nude- 

 aria simplex in its rounded circumference, and its numerous 

 radiating and delicate pseudopodia. It is probable, however, 

 that this form is not identical with Nuclearia. Cienkowski 

 has observed a change in the reverse way, viz. from a rhi- 

 zopod condition into an actively moving flagellate state. 

 This faculty is also possessed by the organism just described, 

 for the pseudopodia are retracted together, and the body 

 gradually begins to move backwards and forwards, the cause 

 of such movement being indiscernible. Finally, when the 



> 'Arch. f. Mikr. Auat.,' Bd. xii, p. 29. 



